Surgical instrument

ABSTRACT

A minimally invasive surgical instrument ( 1 ) comprises an elongate stem ( 2 ) extending between a proximal end ( 3 ) which in use is located externally of an operating space ( 12 ) and a distal end ( 4 ) which in use is located within an operating space ( 12 ). At least portion of the stem ( 2 ) is malleable to facilitate manipulation of the stem ( 2 ) in the operating space ( 12 ) and then to maintain the stem ( 2 ) in the manipulated position and/or orientation within the operating space ( 12 ). The instrument ( 1 ) has an end effector ( 5 ) at the distal end ( 4 ) of the stem ( 2 ), the end effector ( 5 ) comprising a proximal main body ( 6 ) and distal operating means, such as graspers or cutters. The instrument ( 1 ) has at least one joint ( 8, 9 ) for independent movement of the end effector main body ( 6 ) in at least one direction relative to the distal end ( 4 ) of the stem ( 2 ) for enhanced degrees of freedom o the instrument.

INTRODUCTION

[0001] This invention relates to a minimally invasive surgicalinstrument and in particular to an instrument suitable for laparoscopicsurgery, such as hand-assisted laparoscopy.

[0002] Conventional open surgery requires the creation of an incision inthe abdominal wall to allow access to, and visualisation of internalorgans and other anatomical structures. These incisions must be largeenough to accommodate a surgeon's hands and any instruments to beutilised by the surgeon during the surgery. Traditionally the size ofthese incisions has been dictated by the need to see, retract andpalpate internal bodily structures. While a large incision will provideaccess to the interior of the abdomen, such incisions are associatedwith long healing times, are susceptible to infection, and result inunsightly scars.

[0003] Surgical instruments for open surgery are known. For example,U.S. Pat. No. 6,139,563, describes a shaft member operatively coupled toa clamp-type tissue engaging means for use in a mini-laparotomyprocedure. The instrument is suitable for insertion directly through anincision opening into an operating space, and the shaft is movable tomaintain the opening uncluttered for direct visualisation of theoperating space through the opening.

[0004] Laparoscopic surgery is an alternative to open surgery. In thismethod of surgery, the surgeon operates through very small incisionsusing remotely actuated instruments passed through the abdominal wallusing a device called a cannula which creates a working channel. Theseworking channels typically have a radial dimension in the range of from2 to 15 millimetres. Vision is provided using a laparoscope which istypically 20 to 25 centimetres long and uses fibre-optic technology or aCCD camera to provide the operator with a picture of the interior of theabdomen. The abdomen is generally insufflated with a gas such as carbondioxide or nitrogen to create a bubble effect and to provide a viableworking space, known as the pneumoperitoneum, in which the operator mayperform the surgery. Cannulae through which instruments are inserted areconstructed to prevent loss of the insufflation gas through them, whichwould otherwise result in collapse of the pneumoperitoneum.

[0005] The benefits of laparoscopic surgery are numerous. Recovery timeshave been shown to be reduced due to the absence of a large incision.This has benefits for the patient, the health-care organisation andsociety. The benefits to the patient are reduced stay in hospital,faster mobilisation and return to normal activity. The benefits to thehealth care organisation are also due to the reduced stay in hospitalwhich is often the most expensive aspect of health care provision.Society benefits in faster return to work and normal activity of thepatient.

[0006] Some surgical procedures are difficult to performlaparoscopically, for example surgery requiring the removal of largeorgan specimens, such as surgery for removal of the colon.

[0007] Laparoscopic surgical techniques are generally complex andsurgeons tend to require long periods training to master thesetechniques. The surgeon manipulates organs and carries out delicatetasks using remotely actuated instruments. Because the surgeon isinsulated from the material that he is working on, tactile feedback andthe ability to palpate delicate structures is not possible.

[0008] The image viewed by the surgeon is a two dimensional image on avideo screen, without three dimensional perspective of depth, anddistance, and awareness of the proximity of other structures.

[0009] Recently, new surgical techniques have been developed thatcombine the advantages of both open surgery and laparoscopic surgery. Inthese new techniques, surgery is carried out using a laparoscopicapproach with an additional, slightly larger incision to allow thesurgeon to insert a hand into the insufflated abdomen. This is oftenreferred to as hand-assisted laparpscopic surgery (HALS).

[0010] HALS allows surgeons to retain tactile feedback andthree-dimensional perspective. It also permits rapid finger dissection,enhanced retraction capabilities and simplified haemostasis. There areseveral publications in the literature describing procedures carried outusing a hand-assisted approach. These include total and sub-totalcolectomy, rectopexy, Nissen's fundoplication, gastrectomy, splenectomy,nephrectomy, pancreatectomy and others. Some of these procedures werepreviously performed using an open technique only.

[0011] During laparoscopy or HALS, a laparoscopic instrument is passedinto an operating space through a laparoscopic cannula. The instrumentis then moved into a desired position in the operating space. It isfrequently desirable to approach an organ or piece of tissue in theoperating space with the instrument in a particular desired orientation.

[0012] However, conventional laparoscopic instruments are difficult tomanipulate as it is only possible to translate the instrument axiallythrough the opening to the operating space, or to pivot the instrumentabout the opening.

[0013] In this way, the incision point restricts the degrees of freedomof the instrument, and make it difficult to approach an anatomicalstructure in a desired manner within the operating space. The restrictedfreedom of movement may require the surgeon to assume an uncomfortableposition during the procedure leading to surgeon fatigue, and extendedtime periods to complete a procedure.

[0014] To access a desired position in the operating space and/or at adesired orientation in the operating space with the instrument, it maybe necessary to create another opening to the operating space and topass the instrument through a cannula at this other opening into theoperating space. This causes further trauma to the patient.

[0015] Floppy surgical instruments are also known. For example, U.S.Pat. No. 5,779,727 discloses a surgical scissors at the end of aflexible arm for use in laparoscopic surgery. Such floppy instrumentsrestrict the surgeon's freedom of movement as the surgeon must hold thefloppy instrument in a desired position and/or at a desired orientationin the operating space throughout the laparoscopic procedure.

[0016] There is therefore a need for a minimally invasive surgicalinstrument which will facilitate access to a desired site in an openinginto an operating space without restricting the freedom of movement of asurgeon.

STATEMENTS OF INVENTION

[0017] According to the invention, there is provided a minimallyinvasive surgical instrument comprising:—

[0018] an elongate stem extending between a proximal end for locationexternally of an operating space and a distal end for insertion into anoperating space;

[0019] an end effector at the distal end of the stem, the end effectorcomprising a proximal main body;

[0020] at least portion of the stem being malleable to facilitatemanipulation and to maintain the stem in a manipulated position and/ororientation within the operating space; and

[0021] at least one joint for independent movement of the end effectormain body relative to the distal end of the stem.

[0022] In one embodiment of the invention the joint facilitates rotationof the end effector main body about a longitudinal axis of the endeffector relative to the distal end of the stem.

[0023] In another embodiment of the invention the joint facilitatespivoting of the end effector main body relative to the distal end of thestem. In one case the joint comprises a universal joint. In another casethe pivotal joint comprises a ball-and-socket joint. In a further casethe joint comprises a hinge.

[0024] Preferably the instrument comprises a rotational joint and apivoting joint. Ideally the rotational joint is distal of the pivotingjoint.

[0025] In a preferred embodiment the stem has a distal portion adjacentthe distal end of the stem, and the distal portion of the stem ismalleable.

[0026] In one case the stem is malleable substantially along the lengththereof.

[0027] In a preferred case the stem has an intermediate portionintermediate the proximal end of the stem and the distal end of thestem, and the intermediate portion of the stem is rigid.

[0028] The malleability of the malleable portion of the stem may varyalong the length of the malleable portion of the stem.

[0029] In a particulary preferred embodiment the stem comprises at leastone seal to prevent leakage of gas through the stem. The seal may beprovided by a gas-tight sealing jacket around the malleable portion ofthe stem.

[0030] In one case the stem comprises an outer shaft and an innerelongate member. Preferably the seal is provided between the outer shaftand the inner elongate member. Ideally the seal comprises an O-ring.

[0031] The inner member may be at least partially flexible. The innermember may be at least partially rigid. Most preferably a proximalportion of the inner member is rigid and a distal portion of the innermember is flexible.

[0032] In another embodiment at least portion of the stem is of alayered construction. Ideally at least one layer acts as a seal. Mostpreferably at least one layer comprises a spring coil. In another caseat least one layer is a coil braid. At least one layer may be of apolymeric material. Ideally the polymeric material is polyvinylchloride.

[0033] At least one layer may be of a metallic material. Ideally themetallic material is aluminium.

[0034] In another embodiment at least portion of the stem is of alinkage construction. Preferably the inks are interconnected by hinges.

[0035] In a preferred case the end effector main body is mounted to thedistal end of the stem. Ideally the joint is provided in the region ofmounting of the end effector main body to the distal end of the stem.

[0036] In one embodiment the end effector main body is releasablymounted to the distal end of the stem. Preferably the end effector mainbody is threadably mounted to the distal end of the stem.

[0037] The instrument may comprise a lock to selectively preventdemounting of the end effector main body from the distal end of thestem. The lock preferably comprises a lip for engagement in a recess tolimit movement of the end effector main body relative to the stem. Theend effector main body may comprise the lip and the recess may bedefined on the stem. Preferably the lip is movable between a firstposition engaged in the recess and a second disengaged position. Ideallythe recess is sized to facilitate up to 360° rotation of the endeffector main body relative to the distal end of the stem withoutdemounting the end effector main body from the distal end of the stem.

[0038] In another embodiment the end effector main body is fixedlymounted to the distal end of the stem. Ideally the end effector mainbody is mounted to the distal end of the stem by an engagement of atleast one male projection in at least one corresponding female recess.

[0039] In another preferred embodiment the instrument comprises a moverto facilitate independent movement of the end effector main bodyrelative to the distal end of the stem from the proximal end of thestem.

[0040] The instrument preferably comprises a manipulator to facilitatemanipulation of the position and/or orientation of the stem from theproximal end of the stem.

[0041] Desirably the instrument comprises a lock to lock the stem in adesired manipulated position and/or orientation.

[0042] The mover and/or the manipulator and/or the lock may be providedby at least one wire extending along at least portion of the stem.Ideally the wire is coupled to the end effector. The wire may bereleasbly coupled to the end effector. Preferably the wire is threadablycoupled to the end effector.

[0043] The wire may be fixedly coupled to the end effector. Preferablythe wire is coupled to the end effector by an engagement of at leastmale projection in at least one corresponding female recess.

[0044] In a preferred embodiment the wire is slidably received in atleast one guide on the stem. Ideally the wire comprises a stop to limitmovement of the wire.

[0045] Desirably the stem has a proximal portion adjacent a proximal endof the stem, and the proximal portion of the stem is flexible.

[0046] In another embodiment of the invention the stem is extendablefrom a retracted configuration to an extended configuration. The stemmay be telescopically extendable. The stem may be extendable in aconcertina manner.

[0047] In one embodiment the end effector main body comprises anorientation indicator. Preferably the indicator is provided by a knurledor ridged portion of the end effector.

[0048] In another aspect, the invention provides a surgical apparatuscomprising a minimally invasive surgical instrument of the invention anda cannula through which the instrument may be partially inserted.

[0049] The cannula may be at least partially flexible. Ideally a distalportion of the cannula adjacent a distal end of the cannula is flexible.

[0050] According to a further aspect of the invention, there is provideda method of performing minimally invasive surgery comprising the stepsof:—

[0051] providing a surgical instrument, the instrument having a proximalend and a distal end, and at least portion of the instrument beingmalleable;

[0052] partially inserting the instrument through an opening into anoperating space so that the proximal end is located externally of theoperating space and the distal end is located within the operatingspace; and

[0053] manipulating the instrument into a desired position and/ororientation, the manipulated position and/or orientation beingmaintained by the malleable nature of the instrument.

[0054] In one embodiment of the invention the instrument comprises anend effector at the distal end of the instrument, the end effectorcomprising a proximal main body and a distal operator, and the methodcomprises the step of moving the end effector main body in at least onedirection independently relative to the distal end of the instrument.Ideally the end effector main body is rotated about a longitudinal axisof the end effector relative to the distal end of the instrument.

[0055] The end effector main body is preferably pivoted relative to thedistal end of the instrument in at least one direction.

[0056] The instrument may be at least partially manipulated beforepartial insertion of the instrument into the operating space.

[0057] The instrument may be at least partially manipulated afterpartial insertion of the instrument into the operating space.

[0058] The instrument may be at least partially manipulated duringpartial insertion of the instrument into the operating space. Ideallythe instrument is at least partially manipulated by levering theproximal end of the instrument about the opening to the operating spacewhen the instrument is partially inserted through the opening to theoperating space.

[0059] In one preferred case the instrument is at least partiallymanipulated from the proximal end of the instrument externally of theoperating space. The method may comprise the step of inserting a handinto the operating space. Ideally the method comprises the steps of:—

[0060] providing a hand access device;

[0061] mounting the hand access device at an opening to the operatingspace; and

[0062] inserting the hand through the hand access device into theoperating space.

[0063] In another preferred case the instrument is at least partiallymanipulated by the hand from within the operating space.

[0064] In one case the end effector main body is at least partiallymoved relative to the distal end of the instrument from the proximal endof the instrument externally of the operating space.

[0065] In another case the end effector main body is at least partiallymoved relative to the distal end of the instrument by the hand fromwithin the operating space.

[0066] Desirably the method comprises the step of mounting the endeffector main body to the distal end of the instrument. Ideally the endeffector main body is mounted to the distal end of the instrument withinthe operating space. Alternatively the end effector main body may bemounted to the distal end of the instrument externally of the operatingspace.

[0067] In a preferred embodiment the method comprises the step oflocking the instrument in the manipulated position and/or orientation.

[0068] In another case the method comprises the step of extending theinstrument from a retracted configuration to an extended configuration.

[0069] In another preferred embodiment of the invention the methodcomprises the steps of:—

[0070] providing a cannula;

[0071] partially inserting the cannula through the opening to theoperating space; and

[0072] partially inserting the instrument through the cannula into theoperating space.

[0073] The invention provides in one case a method of performingminimally invasive abdominal surgery wherein the operating space is anabdominal cavity.

[0074] The invention provides in another case a method of performinglaparoscopy.

[0075] Another aspect of the invention provides a laparoscopic surgicalinstrument comprising:—

[0076] an elongate stem extending between a proximal end for locationexternally of an operating space and a distal end for insertion into anoperating space;

[0077] the stem comprising at least one seal for gas-tight insertion ofthe stem through an opening to an operating space to maintainpneumoperitoneum in the operating space; and

[0078] at least portion of the stem being malleable to facilitatemanipulation in an operating space and to maintain the stem in amanipulated position and/or orientation within the operating space.

[0079] The seal may be provided at the malleable portion of the stem.

[0080] In one case the seal comprises a gas-tight sealing jacket.

[0081] In another case the seal comprises an O-ring.

[0082] In a further aspect of the invention, there is provided aminimally invasive surgical instrument comprising:—

[0083] an elongate stem extending between a proximal end for locationexternally of an operating space and a distal end for insertion into anoperating space; and

[0084] an end effector at the distal end of the stem;

[0085] the end effector having a low-profile, introductionconfiguration, the radial dimension of the end effector at least in theintroduction configuration being in the range of from 2 mm to 15 mm;

[0086] at least portion of the stem being malleable to facilitatemanipulation in the operating space and to maintain the stem in amanipulated position and/or orientation within the operating space.

[0087] Ideally the end effector is mounted to the distal end of thestem.

[0088] According to yet another aspect, the invention provides aminimally invasive surgical instrument comprising:—

[0089] an elongate stem extending between a proximal end for locationexternally of an operating space and a distal end for insertion into anoperating space;

[0090] the stem having means for mounting of an end effector at thedistal end of the stem;

[0091] the radial dimension of the stem being in the range of from 2 mmto 15 mm; and

[0092] at least portion of the stem being malleable to facilitatemanipulation in the operating space and to maintain the stem in amanipulated position and/or orientation within the operating space.

[0093] In one case, the invention provides a laparoscopic surgicalinstrument.

[0094] In a further aspect of the invention, there is provided acoupling device to selectively prevent demounting of a first shaftreleasably mounted to a second shaft, the device comprising a lip on thefirst shaft for engagement in a recess on the second shaft to limitmovement of the first shaft relative to the second shaft.

[0095] The lip may be slidable along the first shaft between a firstposition engaged in the recess and a second disengaged position.

[0096] Ideally the recess is sized to facilitate up to 360° rotation ofthe first shaft relative to the second shaft without demounting thefirst shaft from the second shaft.

[0097] The malleable nature of the surgical instrument according to theinvention enables the distal end of the instrument to be easilymanipulated into a desired position and/or orientation within theoperating space. This provides the surgeon using the instrument with thefreedom to access sites in the operating space remote from an opening tothe operating space. Most importantly, the instrument maintains thisposition without requiring the surgeon to hold the instrument in themanipulated position and/or orientation.

[0098] The end effector at the distal end of the instrument can be movedrelative to the distal end of the instrument. This enhances the degreesof freedom of the instrument by enabling the end effector to pivot,and/or to rotate, and/or to move in any other suitable manner very closeto a site of interest in the operating space for carrying out a desiredsurgical procedure.

[0099] The joint enables degrees of freedom movement for the endeffector due to the short radius of rotation.

[0100] The surgical instrument of the invention is particularlyapplicable to hand assisted surgery and in particular to surgicaltechniques in which an opening is formed in the abdomen, a sealing handaccess device is placed in the opening and a surgeon's hand is theninserted through the hand access device into the operating space forcarrying out procedures in the operating space. One such sealing deviceis described in our International patent application published undernumber WO-A-00/32117, the entire contents of which are incorporatedherein by reference. The sealing device seals to the wound edge and to asurgeon's arm to maintain pneumoperitoneum in the operating space.

[0101] In this case a surgical instrument is inserted through a cannulainto the operating space and the position and/or orientation of thedistal end of the instrument is controlled by the surgeon's hand. Theend effector can also be moved relative to the distal end of theinstrument by the surgeon's hand to carry out a desired surgicalprocedure within the operating space.

[0102] It will be appreciated that another laparoscopic instrument maybe used alternatively or additionally to the surgeon's hand tomanipulate the instrument and/or to move the end effector relative tothe distal end of the instrument.

BRIEF DESCRIPTION OF THE DRAWINGS

[0103] The invention will be more clearly understood from the followingdescription of some embodiments thereof, given by way of example only,with reference to the accompanying drawings, in which:—

[0104]FIG. 1 is a perspective view of a minimally invasive surgicalinstrument according to the invention;

[0105]FIGS. 2 and 3 are enlarged views of part of the instrument of FIG.1 in different positions of use;

[0106]FIG. 4 is a schematic view of the instrument of FIG. 1 partiallyinserted through a cannula into an operating space;

[0107]FIG. 5 is a schematic view illustrating manipulation of theinstrument of FIG. 4 within the operating space;

[0108]FIG. 6 is a schematic view of the instrument of FIG. 5 aftermanipulation;

[0109]FIGS. 7 and 8 are schematic views illustrating movement of an endeffector of the instrument of FIG. 6 relative to a distal end of theinstrument;

[0110]FIG. 9 is a schematic view of the instrument of FIG. 5 afteranother manipulation;

[0111]FIG. 10 is a side view of a malleable tube part of the instrumentof FIGS. 1 to 9;

[0112]FIG. 11 is a side view of a rigid tube part of the instrument ofFIGS. 1 to 9;

[0113]FIG. 12 is a perspective view of the tube of FIG. 10;

[0114]FIG. 13 is a perspective view of the tube of FIG. 11;

[0115]FIG. 13(a) is a side, partially cross-sectional view of the tubeof FIG. 10;

[0116]FIG. 13(b) is an end view of the tube of FIG. 13(a);

[0117] FIGS. 13(c) and 13(d) are views similar to FIGS. 13(a) and 13(b)illustrating formation of the tube of FIGS. 13(a) and 13(b);

[0118]FIG. 14 is a side view of a flexible cable part of the instrumentof FIGS. 1 to 9;

[0119]FIG. 15 is a side view of a rigid rod part of the instrument ofFIGS. 1 to 9;

[0120]FIG. 16 is a perspective view of the cable of FIG. 14;

[0121]FIG. 17 is a perspective view of the rod of FIG. 15;

[0122]FIG. 17(a) is a side, partially cross-sectional view of the cableof FIG. 14;

[0123]FIG. 17(b) is an end view of the cable of FIG. 17(a);

[0124] FIGS. 17(c) and 17(d) are views similar to FIGS. 17(a) and 17(b)illustrating formation of the cable of FIGS. 17(a) and 17(b);

[0125]FIG. 18 is a side view of a first coupling tube part of theinstrument of FIGS. 1 to 9;

[0126]FIG. 19 is a side view of a second coupling tube part of theinstrument of FIGS. 1 to 9;

[0127]FIG. 20 is a perspective view of the first coupling tube of FIG.18;

[0128]FIG. 21 is a perspective view of the second coupling tube of FIG.19;

[0129]FIG. 22 is a side view of an inner elongate member part of theinstrument of FIGS. 1 to 9;

[0130]FIG. 23 is a perspective view of the inner elongate member of FIG.22;

[0131]FIG. 24(a) is a side view of a spacer element part of theinstrument of FIGS. 1 to 9;

[0132]FIG. 24(b) is a perspective view of the spacer element of FIG. 24(b);

[0133]FIG. 24(c) is a side view of a spring washer part of theinstrument of FIGS. 1 to 9;

[0134]FIG. 24(d) is a perspective view of the spring washer of FIG.24(c);

[0135]FIG. 24(e) is a side view of an end effector connector piece ofthe instrument of FIGS. 1 to 9;

[0136]FIG. 24(f) is a perspective view of the end effector connectorpiece of FIG. 24(e);

[0137]FIGS. 25 and 26 are side and perspective views respectively of theinner elongate member of FIG. 22 inserted through an outer shaft part ofthe instrument of FIGS. 1 to 9;

[0138] FIGS. 27 is an enlarged, side view of part of the assembly ofFIGS. 25 and 26;

[0139]FIG. 28 is an enlarged, side view of another part of the assemblyof FIGS. 25 and 26;

[0140] FIGS. 29(a) to 29(d) are schematic, partially cross-sectionalviews illustrating mounting of the end effector to a distal end of theinstrument of FIGS. 1 to 28;

[0141] FIGS. 30(a) to 30(c) are side, partially cross-sectional viewsillustrating mounting of an end effector to a distal end of anotherminimally invasive surgical instrument according to the invention;

[0142]FIG. 30(d) is an enlarged, perspective view of part of the endeffector and part of the instrument of FIG. 30(a);

[0143]FIG. 31 is a side, partially cross-sectional view of part ofanother minimally invasive surgical instrument according to theinvention;

[0144] FIGS. 32 is a perspective, partially cut-away view of anotherminimally invasive surgically instrument according to the invention;

[0145]FIG. 33 is an enlarged view of part of the instrument of FIG. 32;

[0146]FIG. 34 is a schematic view of the instrument of FIG. 32 partiallyinserted through a cannula into an operating space;

[0147]FIG. 35 is a schematic view illustrating manipulation of theinstrument of FIG. 34 from externally of the operating space;

[0148]FIG. 36 is a schematic view of the instrument of FIG. 35 aftermanipulation;

[0149]FIG. 37 is a perspective view of another minimally invasivesurgical instrument according to the invention;

[0150] FIGS. 38(a) to 40 are schematic views illustrating movement of anend effector of the instrument of FIG. 37 relative to a distal end ofthe instrument from externally of the operating space;

[0151] FIGS. 41(a) to 41(e) are schematic views illustrating movement ofan end effector of another minimally invasive surgical instrumentaccording to the invention relative to a distal end of the instrumentfrom a proximal end of the instrument;

[0152]FIG. 42 is a side view of another minimally invasive surgicalinstrument according to the invention in a retracted configuration;

[0153]FIG. 43 is a side view of the instrument of FIG. 42 in an extendedconfiguration;

[0154]FIG. 44 is a schematic view of another minimally invasive surgicalinstrument according to the invention partially inserted through acannula into an operating space;

[0155]FIG. 45 is a schematic view illustrating manipulation of theinstrument of FIG. 44 within the operating space, and locking of theinstrument in the manipulated position and/or orientation;

[0156]FIG. 46 is a schematic view of the instrument of FIG. 45 aftermanipulation and locking;

[0157]FIGS. 47 and 48 are views similar to FIGS. 13(a) and 13(b) ofanother malleable tube part of a minimally invasive surgical instrumentaccording to the invention;

[0158]FIGS. 49 and 50 are views similar to FIGS. 13(a) and 13(b) ofanother malleable tube part of a minimally invasive surgical instrumentaccording to the invention;

[0159]FIGS. 51 and 52 are views similar to FIGS. 17(a) and 17(b) ofanother flexible cable part of another minimally invasive surgicalinstrument according to the invention; and

[0160]FIGS. 53 and 54 are views similar to FIGS. 17(a) and 17(b) ofanother flexible cable part of another minimally invasive surgicalinstrument according to the invention.

DETAILED DESCRIPTION

[0161] In this specification, the term “malleable” is used to denote anelement which is capable of being manipulated into a desired positionand/or orientation, and which retains this manipulated position and/ororientation under the typical stresses and strains applied when used foran intended purpose with a patient, for example during partial insertionof a laparoscopic instrument through a laparoscopic cannula.

[0162] In this specification, the term “flexible” is used to denote anelement which is capable of being manipulated into a desired positionand/or orientation, but which does not retain this manipulated positionand/or orientation without the assistance of a separate means, such as asurgeon's hand, to hold the flexible element in the manipulated positionand/or orientation.

[0163] Referring to the drawings, and initially to FIGS. 1 to 3 thereof,there is illustrated a minimally invasive surgical instrument 1according to the invention.

[0164] The minimally invasive surgical instrument 1 according to theinvention is particularly suitable for use with a small opening to anoperating space, such as a trocar puncture opening as typically usedduring laparoscopic surgery. The radial dimension of the working channelprovided through a laparoscopic cannula is typically in the range offrom 2 mm to 15 mm.

[0165] An example of use of the surgical instrument of the invention isto carry out a procedure in an abdominal cavity during a minimallyinvasive abdominal surgical procedure.

[0166] The instrument 1 comprises an elongate stem 2 extending between aproximal end 3, which in use is located externally of an operatingspace, and a distal end 4, which in use is inserted into the operatingspace.

[0167] The instrument 1 has an end effector 5, at the distal end 4 ofthe stem 2, and an actuating handle 7 at the proximal end 3 of the stem2. The end effector 5 comprises a proximal main body 6 and distaloperating means, such as grasping fingers or cutting fingers.

[0168] At least portion of the stem 2 is malleable. This facilitatesinsertion of the distal end 4 of the stem 2 into an operating space in alow-profile, substantially straightened configuration, and subsequentmanipulation of the distal end 4 of the stem 2, for example by asurgeon's hand, into a desired position and/or orientation within theoperating space. The malleable stem 2 maintains this manipulatedposition and/or orientation within the operating space.

[0169] As illustrated in FIGS. 2 and 3, the end effector main body 6 ismounted to the distal end 4 of the stem 2. At least one, and in thiscase two, joints 8, 9 are provided in the region of mounting of the endeffector 5 to the distal end 4 of the stem 2. One joint 8 facilitates anindependent rotational movement of the end effector main body 6 about alongitudinal axis running through the end effector 5 relative to thedistal end 4 of the stem 2 (FIG. 2). The other joint 9 facilitates anindependent pivoting movement of the end effector main body 6 relativeto the distal end 4 of the stem 2 (FIG. 3). In this case the pivotingjoint 9 is a hinge joint, and the rotational joint 8 is distal of thepivoting joint 9, as illustrated.

[0170] Referring now to FIGS. 4 to 8, use of the minimally invasivesurgical instrument 1 according to the invention to perform a minimallyinvasive surgical procedure is illustrated.

[0171] A cannula 10 is partially inserted through an opening 11 to anoperating space 12, and the instrument 1 is then partially insertedthrough the cannula 10 so that the proximal end 3 of the stem 2 islocated externally of the operating space 12 and the distal end 4 of thestem 2, with the end effector 5 mounted thereto, is located within theoperating space 12 (FIG. 4).

[0172] The stem 2 is manipulated, for example by a surgeon's gloved hand13, into a desired position and/or orientation within the operatingspace 12 (FIG. 5). The malleable nature of the stem 2 maintains thedistal end 4 of the stem 2 in the desired manipulated position and/ororientation with the operating space 12, even after the stem 2 has beenreleased by the surgeon's hand 13 (FIG. 6).

[0173] When the distal end 4 of the stem 2 is in a desired positionand/or orientation within the operating space 12, the end effector mainbody 6 can be moved, for example rotated about joint 8, in anindependent manner relative to the distal end 4 of the shaft 2 (FIG. 7)for carrying out a desired surgical procedure in the operating space 12,for example cutting away a piece of diseased tissue.

[0174] In this case, the end effector main body 6 is rotated relative tothe distal end 4 of the stem 2 by the surgeon's hand 13, which has beeninserted into the operating space 12 through a hand-access device 14mounted at another opening 15 to the operating space 12 (FIGS. 7 and 8).

[0175] One example of an application of the instrument 1 according tothe invention is to carry out a surgical procedure in the lower pelvis.The malleable stem 2 can be manipulated into a desired position and/ororientation so that the stem 2 extends over the pelvic bone. Thismanipulated position and/or orientation is maintained by the designstrength of the stem 2. The end effector main body 6 can then be movedindependently of the distal end 4 of the stem 2 to approach the gallbladder with the end effector 5, as desired. The enhanced degrees offreedom provided by the joints 8, 9 at the distal end 4 of the malleablestem 2 enables the surgeon to carry out potentially difficult or awkwardsurgical procedures quickly and easily.

[0176] The end effector main body 6 may have a knurled or ridged outersurface to provide tactile indication to the surgeon of the orientationof the end effector 5 relative to the distal end 4 of the stem 2.

[0177] The surgical instrument 1 of the invention is particularlysuitable for use with an at least partially flexible cannula, preferablya distally flexible cannula 10. The flexible cannula 10 enables themalleable instrument 1 to be inserted and moved through the cannula 10in a desired manipulated position and/or orientation. Manipulation ofthe distal end 4 of the stem 2 into a desired position and/ororientation in the operating space 12 may bend or manipulate such aflexible cannula 10, as illustrated in FIG. 9.

[0178] The cannula 10 may also be directly manipulated by the surgeon'sintra-pneumoperitoneal hand 13, and/or by another surgical instrument.

[0179] The stem 2 of the surgical instrument 1 is shown in more detailin FIGS. 10 to 28. The stem 2 comprises an outer shaft 20 and an innerelongate member 23.

[0180] The outer shaft 20 comprises a proximal rigid tube 21 and adistal malleable tube 22 (FIGS. 10 to 13). The malleable tube 22comprises an inner spring coil 22 a, an intermediate spring coil 22 bwith a greater pitch than the inner spring coil 22 a, and an outershrink-wrapped tube 22 c (FIGS. 13(a) and 13(b)).

[0181] The outer tube 22 c acts as a gas-tight sealing jacket around thespring coils 22 a, 22 b. This sealing effect is particularly importantwhen the instrument 1 is used during laparoscopy to prevent insufflationgas from escaping through the malleable tube 22. In this manner,pneumoperitoneum within the operating space 12 is maintained even duringmanipulation of the stem 2.

[0182] To form the tube 22, the intermediate spring coil 22 b is wrappedaround the inner spring coil 22 a (FIGS. 13(c) and 13(d)), and the outertube 22 c is shrink-wrapped around the spring coils 22 a, 22 b.

[0183] The inner elongate member 23 comprises a proximal rigid rod 24and a distal flexible cable 25 (FIGS. 14 to 17).

[0184] The flexible cable 25 comprises a braid of inner wires 25 a andan outer wire coil 25 b (FIGS. 17(a) and 17(b)). To form the cable 25,the outer wire coil 25 b is wrapped around the braid of inner wires 25 a(FIGS. 17(a) and 17(b)).

[0185] The inner elongate member 23 is assembled by inserting a distalend 26 of rod 24 into a proximal end 27 of a first coupling tube 28, andinserting a proximal end 29 of cable 25 into a distal end 30 of thecoupling tube 28.. The rod 24, the cable 25 and the coupling tube 28 arethen silver soldered together to secure the assembly. A distal end 31 ofcable 25 is then inserted into a proximal end 32 of a second couplingtube 33, and the coupling tube 33 is silver soldered to the cable 25 toform the inner elongate member 23, as illustrated in FIGS. 22 and 23.

[0186] The outer shaft 20 is assembled by overlapping a proximal end 34of the malleable tube 22 over a distal end 35 of the rigid tube 21. Aproximal end 151 of a spacer element 150, as illustrated in FIGS. 24(a)and 24(b), is inserted into a distal end 36 of the malleable tube 22until a shoulder 152 on the spacer 150 engages the tube 22. A springwasher 153 is aligned distally of the spacer 150, and an end effectorconnector piece 154 is aligned distally of the washer 153. The springwasher 153 and the end effector connector piece 154 are illustrated inFIGS. 24(c) to 24(f). The assembled inner elongate member 23 is theninserted through the assembled outer shaft 20, as illustrated in FIGS.25 and 26, to form the stem 2 of the surgical instrument 1. A fixing pin155 is inserted through cooperating apertures 156, 157 in the endeffector connector piece 154 and the second coupling tube 33respectively, to secure the stem assembly, as illustrated in detail inFIG. 27.

[0187] An internal O-ring lip seal 162 is provided between a proximalend 161 of the rod 24 and a proximal end 160 of the rigid tube 21, asillustrated in FIG. 28. The O-ring seal 162 is particularly importantwhen the instrument 1 is used during laparoscopy, to preventinsufflation gas from escaping through the space between the outer shaft20 and the inner elongate member 23. In this manner, pneumoperitoneumwithin the operating space is maintained even during movement of theinner elongate member 23 relative to the outer shaft 20.

[0188] FIGS. 29(a) to 29(d) illustrate mounting of the end effector 5 tothe stem 2. The end effector 5 is threadably mounted in a releasablemanner to the distal end 4 of the stem 2 by screwing the end effector 5to the end effector connector piece 154 engaging thread formations onthe end effector 5 with corresponding thread formations on the endeffector connector piece 154 engaging thread formations on the endeffector 5 with corresponding thread formations on the end effectorconnector piece 154, as illustrated in FIGS. 29(a) to 29(d). A distalend 37 of the coupling tube 33 also has thread formations whichthreadingly engage with corresponding thread formations on inner tongue41 in the end effector 5 in a releasable manner during screwing of theend effector 5 to the end effector connector piece 154 (FIGS. 29(a) to29(d)).

[0189] It will be appreciated that the instrument 1 may additionally oralternatively be manipulated externally of the operating space 12 beforeinserting the instrument 1 partially through the flexible cannula 10into the operating space 12.

[0190] It will further be appreciated that the instrument 1 mayadditionally or alternatively be manipulated during the partialinsertion of the instrument 1 through the cannula 10 by levering theproximal end 3 of the stem 2 about the cannula 10 in the opening 11 whenthe instrument 1 is partially inserted through the cannula 10.

[0191] These procedures may aid the surgeon in accessing regions in theoperating space 12 which are laterally remote of the opening 11. Inaddition the surgeon can adapt to the physiological characteristics ofthe patient, for example the thickness of the abdomen wall, or thestrength of the abdomen muscle.

[0192] It will be appreciated that the stem 2 may be malleable along theentire length of the stem 2 provided that the distal end 4 of the stem 2can be manipulated into and maintained in a desired position and/ororientation in the operating space 12.

[0193] It will further be appreciated that the malleability of themalleable portion of the stem 2 may vary along the length of themalleable portion of the stem 2.

[0194] Further it will be appreciated that the malleability of themalleable portion of the stem 2 may be adjusted while the instrument 1is at least partially inserted through the cannula 10 into the operatingspace 12. This may be achieved by, for example, an adjustment mechanismexternally of the operating space 12, such as by two separate wires toadjust the malleability of the stem 2.

[0195] A proximal portion of the stem 2 adjacent a proximal end 3 of thestem 2 may be flexible. This flexible proximal portion enables a surgeonto hold the actuating handle 7, which is jointed to the proximal end 3of the stem 2, in any suitable or comfortable position during use. Thismay provide for a more ergonomic surgical instrument.

[0196] FIGS. 30(a) to 30(d) illustrate mounting of another end effector40 to the stem 2. End effector 40 is similar to the end effector 5 ofFIGS. 1 to 29, and similar elements in FIGS. 30(a) to 30(d) are assignedthe same reference numerals.

[0197] In the case of end effector 40, only one joint, the rotationaljoint 8, is provided in the region of mounting of the main body of theend effector 40 to the distal end 4 of the stem 2 to facilitateindependent rotational movement of the main body of the end effector 40relative to the distal end 4 of the stem 2.

[0198] The end effector 40 is threadably mounted in a releasable mannerto the distal end 4 of the stem 2 by screwing the end effector 40 to theend effector connector piece 154 engaging thread formations on the endeffector 40 with the corresponding thread formations on the end effectorconnector piece 154, as illustrated in FIGS. 30(a) and 30(b). The threadformations on the coupling tube 33 threadingly engage with thecorresponding thread formations on the inner tongue 41 in the endeffector 40 in a releasable manner during screwing of the end effector40 to the end effector connector piece 154 (FIGS. 30(a) and 30(b)).

[0199] The end effector 40 comprises a lip 42 for engagement in a recess43 on the end effector connector piece 154 to selectively limit movementof the main body of the end effector 40 relative to the distal end 4 ofthe stem 2, and thereby prevent demounting of the main body of the endeffector 40 from the distal end 4 of the stem 2. The lip 42 is slidablealong the end effector 40 between a disengaged position (FIG. 30(b)) anda position engaged in the recess 43 (FIG. 30 (c)). In the engagedposition of FIG. 30(c), rotation of the inner elongate member 23relative to the outer shaft 20, and thereby rotation of the end effector40 relative to the end effector connector piece 154, is limited by thelongitudinal movement of the lip 42 in the recess 43. The recess 43 ispreferably sized to facilitate up to 360° rotation of the main body ofthe end effector 40 relative to the end effector connector piece 154without demounting the main body of the end effector 40 from the distalend 4 of the stem 2.

[0200] As illustrated in FIG. 30(d), the lip 42 comprises a plurality ofcorrugations 44 and the recess 43 comprises a plurality of correspondingcorrugations 45, so that in use the corrugations 44 and 45 mate. Thisensures that the rotation of the main body of the end effector 40relative to the end effector connector piece 154 occurs in a step wisemanner.

[0201] Referring to FIG. 31 there is illustrated another end effector50, which is similar to the end effector 40 of FIGS. 30(a) to 30(d), andsimilar elements in FIG. 31 are assigned the same reference numerals. Inthe case of end effector 50, only one joint, the rotational joint 8, isprovided in the region of mounting of the main body of the end effector50 to the distal end 4 of the stem 2 to facilitate independentrotational movement of the main body of the end effector 50 relative tothe distal end 4 of the stem 2.

[0202] The main body of the end effector 50 is fixedly mounted to thedistal end 4 of the stem 2 by means of a plurality of male projections51 on the end effector connector piece 154 which engage in a pluralityof corresponding female recesses 52 on the end effector 50. Theprojections 51 and recesses 52 are configured to enable rotation of themain body of the end effector 50 relative to the distal end 4 of thestem 2.

[0203] The inner tongue 41 in the end effector 50 is fixedly coupled tothe distal end 37 of the coupling tube 33, as illustrated, in a mannerwhich prevents rotation of the main body of the end effector 40 relativeto the coupling tube 33.

[0204] Referring now to FIGS. 32 to 36 there is illustrated anothersurgical instrument 70 according to the invention, which is similar tothe surgical instrument 1 of FIGS. 1 to 29, and similar elements inFIGS. 32 to 36 are assigned the same reference numerals.

[0205] The instrument 70 comprises means to facilitate manipulation ofthe position and/or orientation of the stem 2 from the proximal end 3 ofthe stem 2, which in use is located externally of the operating space12. The means is provided by at least one, and in this case four,malleable wires 71 extending along at least portion of the stem 2 (FIGS.32 and 33). The wires 71 are slidably received in guides 72 on the stem2, with stops at the ends of the wires 71 to limit movement of the wires71. The wires 71 are connected proximally by a clamping arrangement to acontrol dial 74 on the actuating handle 7.

[0206] In use, the instrument 70 is partially inserted through thecannula 10 so that the end effector 5 is located within the operatingspace 12 (FIG. 34). The control dial 74 is then actuated by thesurgeon's hand 13 externally of the operating space 12 to pull on thewires 71 and thereby manipulate the distal end 4 of the stem 2 into adesired position and/or orientation in the operating space 12 (FIG. 35).

[0207] The malleable nature of the stem 2 and the wires 71 maintains thedistal end 4 of the stem 2 in the desired position and/or orientation inthe operating space 12 without requiring assistance from a separatemeans to hold the distal end 4 of the stem 2 in the manipulated positionand/or orientation (FIG. 36).

[0208] Referring to FIGS. 37 to 40, there is illustrated anothersurgical instrument 80 according to the invention, which is similar tothe surgical instrument 70 of FIGS. 32 to 36, and similar elements inFIGS. 37 to 40 are assigned the same reference numerals.

[0209] In this case, a toggle switch 81 is provided on the actuatinghandle 7. The switch 81 is moveable between a position R for rotation ofthe main body of the end effector 5 relative to the distal end 4 of thestem 2, and a position H for pivoting or hinging movement of the mainbody of the end effector 5 relative to the distal end 4 of the stem 2(FIG. 37).

[0210] With the toggle switch 81 in position R, the control dial 74 maybe actuated by the surgeon's hand 13 externally of the operating space12 to rotate the main body of the end effector 5 relative to the distalend 4 of the stem 2 (FIGS. 38(a), 38(b) and 40). With the toggle switch81 in position H, the control dial 74 may be actuated by the surgeon'shand 13 externally of the operating space 12 to pivot the main body ofthe end effector 5 relative to the distal end 4 of the stem 2 (FIGS.38(c), 38(d) and 39).

[0211] Referring to FIGS. 41(a) to 41(e) there is illustrated anothersurgical instrument 60 according to the invention, which is similar tothe surgical instrument 80 of FIGS. 37 to 40, and similar elements inFIGS. 41(a) to 41(e) are assigned the same reference numerals.

[0212] In this case, the pivoting joint 9 is a universal joint, thejoint 9 facilitating an independent pivoting movement of the endeffector main body 6 relative to the distal end 4 of the stem 2.Actuation of a joystick control 61 may be employed to pivot the endeffector main body 6 relative to the distal end 4 of the stem 2 (FIG.41(a)).

[0213] The rotational joint 8 facilitates an independent rotationalmovement of the end effector main body 6 about a longitudinal axisrunning through the end effector 5 relative to the distal end 4 of thestem 2. Actuation of the control dial 74 may be employed to rotate theend effector main body 6 relative to the distal end 4 of the stem 2(FIG. 41 (b)).

[0214] Two malleable, lateral wires 62 extend through the stem 2 to thepivoting joint 9 to which the wires 62 are coupled for pivoting of themain body 6 of the end effector 5 relative to the distal end 4 of thestem 2 by actuation of the joystick control 61 (FIG. 41(d)). Amalleable, central wire 63 extends through the stem 2 to the rotatingjoint 8 to which the wire 63 is coupled for rotation of the main body 6of the end effector 5 relative to the distal end 4 of the stem 2 byactuation of the control dial 74 (FIG. 41 (d)). The central wire 63 isalso operatively coupled to actuate the jaws of the end effector 5.

[0215] It will be appreciated that any desired combination of pivotingand rotating of the end effector main body 6 relative to the distal end4 of the stem 2 may be achieved with the surgical instrument 60 by anysuitable actuation of the joystick control 61 and/or the control dial 74(FIG. 41(e)).

[0216] It will further be appreciated that a ball-and-socket joint mayalternatively be used for the pivoting joint 9.

[0217]FIGS. 42 and 43 illustrate another surgical instrument 90according to the invention, which is similar to the surgical instrument1 of FIGS. 1 to 29, and similar elements in FIGS. 42 and 43 are assignedthe same reference numerals. In this case, the stem 2 is extendable froma retracted configuration (FIG. 42) to an extended configuration (FIG.43) in a telescopic manner.

[0218] It will be appreciated that the stem 2 may alternatively beextendable in a concertina manner, or in any other suitable manner.

[0219] The extendable stem 2 facilitates enhanced access for the endeffector 5 at the distal end 4 of the stem 2 to desired locations in theoperating space 12 for performing surgical procedures. The extendableaspect of the instrument 90 enables at least portion of the stem 2 to berigid or flexible.

[0220] Referring to FIGS. 44 to 46, there is illustrated anothersurgical instrument 100 according to the invention, which is similar tothe surgical instrument 1 of FIGS. 1 to 29, and similar elements inFIGS. 44 to 46 are assigned the same reference numerals.

[0221] In this case, the instrument 100 comprises means to lock thedistal end 4 of the stem 2 in a desired manipulated position and/ororientation within the operating space 12.

[0222] The locking means ensures that the distal end 4 of the stem 2maintains its desired manipulated position and/or orientation within theoperating space 12, even if the stem 2 is inadvertently knocked againstby the surgeon's hand 13, or by a laparoscopic instrument, or by aninternal organ. The locking means also ensures that the malleable stem 2maintains the desired position and/or orientation during insertion ofthe instrument 100 through the cannula 10. This is particularlyadvantageous if the cannula 10 is not completely flexible.

[0223] The means is provided, in this case, by at least one malleablewire 71, similar to wires 71 described previously with reference to FIG.33, extending along at least portion of the stem 2. The wires 71 areslidably received in co-operating guides 72 on the stem 2, with stops atends of the wires 71 to limit movement of the wires 71, and the wires 71are connected proximally by a clamping arrangement to a locking switch101 on the actuating handle 7 (FIG. 44).

[0224] In use, the instrument 100 is partially inserted through thecannula 10 into the operating space 12 so that the end effector 5 islocated within the operating space 12. The distal end 4 of the stem 2 ismanipulated into a desired position and/or orientation within theoperating space 12 by the surgeon's hand 13, and the switch 101 is movedfrom the open position to the locked position to clamp the tensionedwires 71 in place (FIG. 45). With the switch 101 in the locked position,the distal end 4 of the stem 2 is locked in the manipulated positionand/or orientation for increased security (FIG. 46).

[0225] It will be appreciated that the malleable wires 71 mayalternatively be positioned along the interior of the stem 2, orembedded within the stem 2. It will further be appreciated that acoating, such as a low friction coating, may be provided over the wires71.

[0226] An alternative construction for the malleable tube 22 of theouter shaft 20 of the stem 2 is illustrated in FIGS. 47 and 48. The tube22, in this case, comprises an inner flexible tube 202 typically of amaterial such as polyvinylchloride (PVC), an intermediate tube 201,typically of a metal such as aluminium, and an outer malleable tube 200,typically of a material such as PVC. The PVC tubing 200, 202 helps toprevent kinking in the aluminium tube 201.

[0227]FIGS. 49 and 50 illustrate another alternative construction forthe malleable tube 22. In this case, the tube 22 comprises a series ofhinge joints 204 enclosed in an outer shrink-wrapped tube 203.

[0228] An alternative construction for the flexible cable 25 of theinner elongate member 23 of the stem 2 is illustrated in FIGS. 51 and52. The cable 25, in this case, comprises a braid of inner wires 210.

[0229]FIGS. 53 and 54 illustrate another alternative construction forthe flexible cable 25. In this case, the cable 25 comprises a series ofchain linkages 211.

[0230] It will be appreciated that the instrument 1 is also suitable foruse with a rigid cannula.

[0231] In one minimally invasive surgical instrument according to theinvention, the end effector is mounted to the distal end of the stembefore inserting the instrument partially through the laparoscopiccannula into an operating space. The end effector has a low-profileintroduction configuration, and in this configuration the end effectoris small enough, for example with a radial dimension in the range offrom 2 mm to 15 mm, to be passed directly through the laparoscopiccannula.

[0232] In another minimally invasive surgical instrument according tothe invention, the stem of the instrument is inserted partially througha laparoscopic cannula into an operating space, and the end effector ismounted to the distal end of the stem within the operating space. Thestem of the instrument is small enough, for example with a radialdimension in the range of from 2 mm to 15 mm, to be passed directlythrough the laparoscopic cannula. The end effector may be inserted intothe operating space by any suitable means, such as through a sealingaccess device, such as described in our International patent applicationpublished under number WO-A-00/32117.

[0233] The invention is not limited to the embodiments hereinbeforedescribed, with reference to the accompanying drawings, which may bevaried in construction and detail.

1. A minimally invasive surgical instrument comprising:— an elongate stem extending between a proximal end for location externally of an operating space and a distal end for insertion into an operating space; an end effector at the distal end of the stem, the end effector comprising a proximal main body; at least portion of the stem being malleable to facilitate manipulation and to maintain the stem in a manipulated position and/or orientation within the operating space; and at least one joint for independent movement of the end effector main body relative to the distal end of the stem.
 2. An instrument as claimed in claim 1 wherein the joint facilitates rotation of the end effector main body about a longitudinal axis of the end effector relative-to the distal end of the stem.
 3. An instrument as claimed in claim 1 or 2 wherein the joint facilitates pivoting of the end effector main body relative to the distal end of the stem.
 4. An instrument as claimed in claim 2 or 3 wherein the pivotal joint comprises a universal joint.
 5. An instrument as claimed in claim 2 or 3 wherein the joint comprises a ball-and-socket joint.
 6. An instrument as claimed in claim 3 wherein the joint comprises a hinge.
 7. An instrument as claimed in any preceding claim wherein the instrument comprises a rotational joint and a pivoting joint.
 8. An instrument as claimed in claim 7 wherein the rotational joint is distal of the pivoting joint.
 9. An instrument as claimed in any preceding claim wherein the stem has a distal portion adjacent the distal end of the stem, and the distal portion of the stem is malleable.
 10. An instrument as claimed in any preceding claim wherein the stem is malleable substantially along the length thereof.
 11. An instrument as claimed in claim 9 wherein the stem has an intermediate portion intermediate the proximal end of the stem and the distal end of the stem, and the intermediate portion of the stem is rigid.
 12. An instrument as claimed in any preceding claim wherein the malleability of the malleable portion of the stem varies along the length of the malleable portion of the stem.
 13. An instrument as claimed in any preceding claim wherein the stem comprises at least one seal to prevent leakage of gas through the stem.
 14. An instrument as claimed in claim 13 wherein the stem comprises an outer shaft and an inner elongate member.
 15. An instrument as claimed in claim 13 or 14 wherein the seal is provided by a gas-tight sealing jacket around the malleable portion of the stem.
 16. An instrument as claimed in claim 14 wherein the seal is provided between the outer shaft and the inner elongate member.
 17. An instrument as claimed in claim 16 wherein the seal comprises an O-ring.
 18. An instrument as claimed in any of claims 14 to 17 wherein the inner member is at least partially flexible.
 19. An instrument as claimed in any of claims 14 to 18 wherein the inner member is at least partially rigid.
 20. An instrument as claimed in claims 18 and 19 wherein a proximal portion of the inner member is rigid and a distal portion of the inner member is flexible.
 21. An instrument as claimed in any preceding claim wherein at least portion of the stem is of a layered construction.
 22. An instrument as claimed in claim 21 wherein at least one layer acts as a seal.
 23. An instrument as claimed in claim 21 or 22 wherein at least one layer comprises a spring coil.
 24. An instrument as claimed in any of claims 21 to 23 wherein at least one layer is a coil braid.
 25. An instrument as claimed in any of claims 21 to 24 wherein at least one layer is of a polymeric material.
 26. An instrument as claimed in claim 25 wherein the polymeric material is polyvinylchloride.
 27. An instrument as claimed in any of claims 21 to 26 wherein at least one layer is of a metallic material.
 28. An instrument as claimed in claim 27 wherein the metallic material is aluminium.
 29. An instrument as claimed in any preceding claim wherein at least portion of the stem is of a linkage construction.
 30. An instrument as claimed in claim 29 wherein the links are interconnected by hinges.
 31. An instrument as claimed in any preceding claim wherein the end effector main body is mounted to the distal end of the stem.
 32. An instrument as claimed in claim 31 wherein the joint is provided in the region of mounting of the end effector main body to the distal end of the stem.
 33. An instrument as claimed in claim 31 or 32 wherein the end effector main body is releasably mounted to the distal end of the stem.
 34. An instrument as claimed in claim 33 wherein the end effector main body is threadably mounted to the distal end of the stem.
 35. An instrument as claimed in claim 33 or 34 wherein the instrument comprises a lock to selectively prevent demounting of the end effector main body from the distal end of the stem.
 36. An instrument as claimed in claim 35 wherein the lock comprises a lip for engagement in a recess to limit movement of the end effector main body relative to the stem.
 37. An instrument as claimed in claim 36 wherein the end effector main body comprises the lip and the recess is defined on the stem.
 38. An instrument as claimed in claim 36 or 37 wherein the lip is movable between a first position engaged in the recess and a second disengaged position.
 39. An instrument as claimed in any of claims 36 to 38 wherein the recess is sized to facilitate up to 360° rotation of the end effector main body relative to the distal end of the stem without demounting the end effector main body from the distal end of the stem.
 40. An instrument as claimed in claim 31 or 32 wherein the end effector main body is fixedly mounted to the distal end of the stem.
 41. An instrument as claimed in claim 40 wherein the end effector main body is mounted to the distal end of the stem by an engagement of at least one male projection in at least one corresponding female recess.
 42. An instrument as claimed in any preceding claim wherein the instrument comprises a mover to facilitate independent movement of the end effector main body relative to the distal end of the stem from the proximal end of the stem.
 43. An instrument as claimed in any preceding claim wherein the instrument comprises a manipulator to facilitate manipulation of the position and/or orientation of the stem from the proximal end of the stem.
 44. An instrument as claimed in any preceding claim wherein the instrument comprises a lock to lock the stem in a desired manipulated position and/or orientation.
 45. An instrument as claimed in any of claims 42 to 44 wherein the mover and/or the manipulator and/or the lock is provided by at least one wire extending along at least portion of the stem.
 46. An instrument as claimed in claim 45 wherein the wire is coupled to the end effector.
 47. An instrument as claimed in claim 46 wherein the wire is releasably coupled to the end effector.
 48. An instrument as claimed in claim 47 wherein the wire is threadably coupled to the end effector.
 49. An instrument as claimed in claim 46 wherein the wire is fixedly coupled to the end effector.
 50. An instrument as claimed in claim 49 wherein the wire is coupled to the end effector by an engagement of at least male projection in at least one corresponding female recess.
 51. An instrument as claimed in any of claims 45 to 50 wherein the wire is slidably received in at least one guide on the stem.
 52. An instrument as claimed in any of claims 45 to 51 wherein the wire comprises a stop to limit movement of the wire.
 53. An instrument as claimed in any preceding claim wherein the stem has a proximal portion adjacent a proximal end of the stem, and the proximal portion of the stem is flexible.
 54. An instrument as claimed in any preceding claim wherein the stem is extendable from a retracted configuration to an extended configuration.
 55. An instrument as claimed in claim 54 wherein the stem is telescopically extendable.
 56. An instrument as claimed in claim 54 wherein the stem is extendable in a concertina manner.
 57. An instrument as claimed in any preceding claim wherein the end effector main body comprises an orientation indicator.
 58. An instrument as claimed in claim 57 wherein the indicator is provided by a knurled or ridged portion of the end effector.
 59. A surgical apparatus comprising a minimally invasive surgical instrument as claimed in any preceding claim and a cannula through which the instrument may be partially inserted.
 60. An apparatus as claimed in claim 59 wherein the cannula is at least partially flexible.
 61. An apparatus as claimed in claim 60 wherein a distal portion of the cannula adjacent a distal end of the cannula is flexible.
 62. A method of performing minimally invasive surgery comprising the steps of:— providing a surgical instrument, the instrument having a proximal end and a distal end, and at least portion of the instrument being malleable; partially inserting the instrument through an opening into an operating space so that the proximal end is located externally of the operating space and the distal end is located within the operating space; and manipulating the instrument into a desired position and/or orientation, the manipulated position and/or orientation being maintained by the malleable nature of the instrument.
 63. A method as claimed in claim 62 wherein the instrument comprises an end effector at the distal end of the instrument, the end effector comprising a proximal main body and a distal operator, and the method comprises the step of moving the end effector main body in at least one direction independently relative to the distal end of the instrument.
 64. A method as claimed in claim 63 wherein the end effector main body is rotated about a longitudinal axis of the end effector relative to the distal end of the instrument.
 65. A method as claimed in claim 63 or 64 wherein the end effector main body is pivoted relative to the distal end of the instrument in at least one direction.
 66. A method as claimed in any of claims 62 to 65 wherein the instrument is at least partially manipulated before partial insertion of the instrument into the operating space.
 67. A method as claimed in any of claims 62 to 65 wherein the instrument is at least partially manipulated after partial insertion of the instrument into the operating space.
 68. A method as claimed in any of claims 62 to 66 wherein the instrument is at least partially manipulated during partial insertion of the instrument into the operating space.
 69. A method as claimed in claim 68 wherein the instrument is at least partially manipulated by levering the proximal end of the instrument about the opening to the operating space when the instrument is partially inserted through the opening to the operating space.
 70. A method as claimed in any of claims 62 to 69 wherein the instrument is at least partially manipulated from the proximal end of the instrument externally of the operating space.
 71. A method as claimed in any of claims 62 to 70 wherein the method comprises the step of inserting a hand into the operating space.
 72. A method as claimed in claim 71 wherein the method comprises the steps of:— providing a hand access device; mounting the hand access device at an opening to the operating space; and inserting the hand through the hand access device into the operating space.
 73. A method as claimed in claim 71 or 72 wherein the instrument is at least partially manipulated by the hand from within the operating space.
 74. A method as claimed in any of claims 63 to 73 wherein the end effector main body is at least partially moved relative to the distal end of the instrument from the proximal end of the instrument externally of the operating space.
 75. A method as claimed in claim 71 or 72 wherein the end effector main body is at least partially moved relative to the distal end of the instrument by the hand from within the operating space.
 76. A method as claimed in any of claims 63 to 75 wherein the method comprises the step of mounting the end effector main body to the distal end of the instrument.
 77. A method as claimed in claim 76 wherein the end effector main body is mounted to the distal end of the instrument within the operating space.
 78. A method as claimed in claim 76 wherein the end effector main body is mounted to the distal end of the instrument externally of the operating space.
 79. A method as claimed in any of claims 62 to 78 wherein the method comprises the step of locking the instrument in the manipulated position and/or orientation.
 80. A method as claimed in any of claims 62 to 79 wherein the method comprises the step of extending the instrument from a retracted configuration to an extended configuration.
 81. A method as claimed in any of claims 62 to 80 wherein the method comprises the steps of:— providing a cannula; partially inserting the cannula through the opening to the operating space; and partially inserting the instrument through the cannula into the operating space.
 82. A method of performing minimally invasive abdominal surgery as claimed in any of claims 62 to 81 wherein the operating space is an abdominal cavity.
 83. A method of performing laparoscopy as claimed in any of claims 62 to
 82. 84. A method of performing minimally invasive surgery substantially as hereinbefore described with reference to the accompanying drawings.
 85. A laparoscopic surgical instrument comprising:— an elongate stem extending between a proximal end for location externally of an operating space and a distal end for insertion into an operating space; the stem comprising at least one seal for gas-tight insertion of the stem through an opening to an operating space to maintain pneumoperitoneum in the operating space; and at least portion of the stem being malleable to facilitate manipulation in an operating space and to maintain the stem in a manipulated position and/or orientation within the operating space.
 86. An instrument as claimed in claim 85 wherein the seal is provided at the malleable portion of the stem.
 87. An instrument as claimed in claim 85 or 86 wherein the seal comprises a gas-tight sealing jacket.
 88. An instrument as claimed in any of claims 85 to 87 wherein the seal comprises an O-ring.
 89. A minimally invasive surgical instrument comprising:— an elongate stem extending between a proximal end for location externally of an operating space and a distal end for insertion into an operating space; and an end effector at the distal end of the stem; the end effector having a low-profile, introduction configuration, the radial dimension of the end effector at least in the introduction configuration being in the range of from 2 mm to 15 mm; at least portion of the stem being malleable to facilitate manipulation in the operating space and to maintain the stem in a manipulated position and/or orientation within the operating space.
 90. An instrument as claimed in claim 89 wherein the end effector is mounted to the distal end of the stem.
 91. A minimally invasive surgical instrument comprising:— an elongate stem extending between a proximal end for location externally of an operating space and a distal end for insertion into an operating space; the stem having means for mounting of an end effector at the distal end of the stem; the radial dimension of the stem being in the range of from 2 mm to 15 mm; and at least portion of the stem being malleable to facilitate manipulation in the operating space and to maintain the stem in a manipulated position and/or orientation within the operating space.
 92. A laparoscopic surgical instrument as claimed in any of claims 1 to 58 or 85 to
 91. 93. A minimally invasive surgical instrument substantially as hereinbefore described with reference to the accompanying drawings.
 94. A coupling device to selectively prevent demounting of a first shaft releasably mounted to a second shaft, the device comprising a lip on the first shaft for engagement in a recess on the second shaft to limit movement of the first shaft relative to the second shaft.
 95. A device as claimed in claim 94 wherein the lip is slidable along the first shaft between a first position engaged in the recess and a second disengaged position.
 96. A device as claimed in claim 94 or 95 wherein the recess is sized to facilitate up to 360° rotation of the first shaft relative to the second shaft without demounting the first shaft from the second shaft.
 97. A coupling device substantially as hereinbefore described with reference to the accompanying drawings. 